Worldwide losses in stored products, caused by insects, have been estimated to be between five and ten percent. Heavier losses occurring in the tropics may reach 30% and the net value of losses in storage in the United States has been placed at over $200 million annually. Such loss may reach up to 40%, in countries where modern storage technologies have not been introduced like Ethiopia. These and other factors mentioned in the introductory part of this book are evidences that indicate the relevance of both primary and secondary insect pests as pests of stored products. Therefore, there is a...